Lintel glossary: Common terms, explained

Specifying lintels for a job? While doing so, you might have come across several lintel terminologies that aren’t familiar.

To make things a bit easier for you, we’ve created this glossary of common lintel terms and phrases. From wall cavities to thermal breakage, master the world of lintel knowledge, here.

What is a wall cavity?

A wall cavity is the gap contained between outer and inner leaf of masonry or in case of timber frame walls – between the outer leaf of masonry and structural timber frame.

Cavities in the wall can be unfilled, partially filled or fully filled with insulation.

What does clear span mean?

Clear span or clear opening is the distance between lintel supports.

What does DPC mean?

‘DPC’ stands for damp proof course, which is a waterproof barrier that sits within the walls of a property to reduce the build-up of moisture.

Polyethylene-based DPC is used in conjunction with lintels to provide a slope so that water can escape, and a moisture barrier to prevent excessive damp.

What does galvanised mean?

Galvanisation is the process of applying a protective coating to metals like steel or iron. The galvanisation process involves dipping the material in a bath of molten zinc. This leaves behind a thin coating on top of the metal, making it more corrosion resistant.

All Catnic lintels are made of hot-dip galvanised steel and most are additionally polyester powder coated.

What is a leaf?

Cavity walls are made of two layers of masonry separated by the cavity. The layer facing inside of the building is called inner leaf, while the one facing the outside is called the outer leaf. Loads over the openings in cavity walls can be supported by separate or cavity wall lintels. Separated lintels options mean each masonry leaf is supported by a separate lintel, while a cavity wall lintel provides simultaneous support of both leaves.

What is a load ratio?

Load ratio describes load distribution between the masonry leaves in cavity wall.

For example, if the load over the opening is 20 kN and the load ratio inner to outer is 19:1, that means the load on the inner leaf is 19 kN and the load on the outer leaf is 1 kN.

In the case of cavity wall lintels there is a range of load ratios in which the lintel is designed to work in order to achieve its Safe Working Load (SWL). For example, if the load ratio inner to outer is 1:1/3:1 and the SWL is 20 kN, that means this lintel can support 20 kN, providing the load is distributed between 10 kN: 10 kN inner to outer leaf and 15 kN:5kN inner to outer leaf.

What is a thermal break?

Thermal break is an element with low thermal conductivity separating materials of higher thermal conductivity. Thermal break eliminates or significantly reduces thermal bridging. The finest example of thermal break is the EPS insulation block in Catnic Thermally Broken Lintels. The EPS core completely separates two steel elements of lintel, reducing heat transfer (energy loss) from the inner to the outer leaf .

Read more: 5 benefits of using thermally broken lintels

What does W/mk mean?

W/mK is a unit of thermal conductivity and stands for Watts per meter-Kelvin.

It expresses the amount of energy (in Watts) transferred through a material with a thickness of one meter when the temperature difference between both surfaces of material is one Kelvin. Materials with low thermal conductivity value are used for manufacturing thermal insulators such as polystyrene, mineral wool, PIR.

Thermal conductivity is also known as lambda (λ) value or k value.

More lintel guidance, from Catnic

Picking lintels can be a challenge. Let the experts help. At Catnic, we’ve been manufacturing lintels for centuries, and have built a reputation as the go-to supplier for thousands of contractors and developers across the globe. Need more help? Get in touch with our team today.